1. Field of the Invention
The present invention relates to the field of protective coatings to be used during coating operations of various surfaces, such as surfaces of automotive parts of motor vehicles.
2. Description of the Prior Art
It is well known that painting or coating operations often require masking of certain portions of the object to be painted to prevent overspray. For example, it is often necessary to mask parts on a vehicle (e.g., a motor vehicle) from paint overspray. On occasion, it is necessary to mask painted portions of a vehicle from paints of a different color.
Currently, paper or plastic film is often used as a mask. Two sided tape is often applied to the edges of the cut mask to adhere the mask to the primed surface. Once the top coat of paint is applied, the paint is either air dried or oven dried. The mask is then thrown away and disposed of as land fill. For specific masking applications, inexpensive foam (“Styrofoam”) blocks are also often used as masks and then discarded after painting and drying by room air temp or oven conditions. Furthermore, even when done carefully, defects in such masks may allow paint to contact surfaces that are desired to be protected.
Spray-on chemical masking solutions have been proposed to purportedly solve the problem of protecting surfaces during coating processing operations. However, such techniques have often not found extensive use. Some of the proposed liquid chemical masks have been unsuitable for application to portions of a vehicle because of damage which would potentially occur to the protected portions of the vehicle. In addition, masks that require solvents for removal are problematic in view of the increasing regulation of disposal of solvents as environmental regulation becomes stricter with time. Other such compositions are difficult to apply, difficult to remove, excessively costly, or the like.
From the above it is seen that an improved masking material that is easily applied and removed, that provides good surface protection, that is economical, and whose use entails little or no environmental impact is needed. In addition, it is known that coating overspray, such as paints, can be collected, processed and reused as filler or the like. A masking material that would facilitate this process would be highly desirable.
Woodhall et al. has disclosed various masking materials based on dextrin. See U.S. Pat. Nos. 5,876,791, 5,362,786; 5,411,760; 5,523,117; 5,302,413 and 5,186,978. In addition, in U.S. Pat. No. 6,117,485 to Woodhall et al. discloses fluid masking materials based on dextrin or cellulose derivatives. The disclosure of all of these patents to Woodhall et al. are all incorporated herein by reference.